JP2881128B2 - Image forming device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for forming a visible image on the surface of a flexible recording medium, such as paper, based on input information. The present invention relates to an image forming apparatus including a laser printer and the like.

[0002]

2. Description of the Related Art Conventionally, as this type of image forming apparatus,
There is an electronic copying machine shown in FIG. 5 using the Carlson method. In this electronic copying machine, an image is formed based on input information as follows.

[0003] A drum 8 provided with a semiconductor layer called a photoreceptor on the outer surface is rotated, and a corona charger 1 is used.
In a dark place, the photoconductor is charged using corona discharge. Next, the original (input information) to be copied is irradiated with light by the exposure device 2, and an electrostatic latent image having the same pattern as the original is formed on the photoconductor. Next, colored fine particles called toner charged to the opposite polarity to the electrostatic latent image are sprinkled on the photoreceptor by the developing device 3. This toner is
Carbon black or the like is a resin fine powder having a particle size of several μm to 50 μm added to the surface or the whole thereof,
A magnetic powder of about 0.1 to 0.5 μm is dispersed in the resin. Next, the transfer unit 4 transfers a copy image of the toner on the photosensitive member to a white recording paper by electrostatic force.
Next, the fixing device 5 applies heat to the toner to melt it, so that the toner permeates between the fibers of the recording paper and is fixed to the recording paper. Next, the photosensitive member is neutralized by a static eliminator 6 constituting a cleaning device, and the residual toner is cleaned by a cleaner 7 also constituting a cleaning device, and the photosensitive member is returned to an initial state. This photoreceptor is used repeatedly. Such a series of processing is completed within a few seconds.

[0004]

However, in the above-mentioned conventional image forming apparatus, corona discharge is used in the charger 1 for charging the surface of the photoreceptor and the static eliminator 6 for discharging the surface of the photoreceptor. There was a problem. That is,
If the corona discharge is used for charging or discharging the photoreceptor, ozone, NOx, and dust are generated during the corona discharge, and the electrodes, which are peripheral components of the corona discharge unit, are oxidized, and the peripheral components deteriorate. In addition, it may cause a fire or the like due to corona discharge. Further, the generation of ozone and NOx is not preferable in the global environment.

The present invention has been made in order to solve the above problems, and has no adverse effect on the surrounding environment during use, has excellent use durability, and has excellent safety. The purpose is to provide.

[0006]

That is, the present invention relates to a substrate formed in a closed loop shape and moving along the closed loop, a charging device for charging a photosensitive layer surface formed on an outer peripheral surface of the substrate, and a charging device. Exposure means for forming an electrostatic latent image corresponding to the image to be formed by exposing the photosensitive layer surface,
Developing means for attaching colored fine particles to the electrostatic latent image, transfer means for transferring the colored fine particles attached to the area of the electrostatic latent image to a recording medium, and fixing means for fixing the colored fine particles transferred to the recording medium And a cleaning means for cleaning colored fine particles remaining on the surface of the photosensitive layer, wherein the base is formed of a light element, and the charging means transmits X through the base and the photosensitive layer. X-ray generation means for charging provided in a closed loop for ionizing the atmosphere on the surface of the photosensitive layer by irradiation with rays, and electric field applying means for guiding gas ions generated by the ionization to the surface of the photosensitive layer by an electric field. Closed means for ionizing the air on the photosensitive layer on which the colored fine particles remain by irradiation of X-rays transmitted through the substrate and the photosensitive layer and generating carriers in the photosensitive layer Characterized in that it consists erasing X-ray generating means provided within.

According to the invention, the X-rays emitted from the charging X-ray generation means in the charging means pass through the base and generate gas ions on the photosensitive layer. The gas ions are guided to the surface of the photosensitive layer by the electric field generated by the electric field applying means, and the surface of the photosensitive layer is charged.

Further, the X-rays emitted from the erasing X-ray generating means in the cleaning means also pass through the substrate and generate gas ions on the photosensitive layer. The colored particles remaining on the surface of the photosensitive layer are neutralized by the gas ions. The X-rays emitted from the erasing X-ray generating means generate carriers in the photosensitive layer. This carrier causes the electrostatic latent image formed on the photosensitive layer to disappear.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Various embodiments of an image forming apparatus according to the present invention will be described below with reference to the accompanying drawings. In each of the drawings, the same elements are denoted by the same reference numerals, and description thereof is omitted.

(Embodiment 1) FIG. 1 shows a basic configuration of an image forming apparatus according to the present embodiment. In FIG. 1, the same parts as those in FIG. 5 are denoted by the same reference numerals. FIG. 2 is a perspective view showing a charging unit 11 and a cleaning unit 12, which are characteristic parts of the image forming apparatus. The image forming apparatus according to the present embodiment is characterized by a charging unit 11 and a cleaning unit (cleaning unit) 12, and each unit of an exposing unit 2, a developing unit 3, a transfer unit 4 and a fixing unit 5 is a conventional unit shown in FIG. Is used. As a recording medium for forming an image, a flexible medium such as paper is used. Also, by changing the light irradiation control means as the exposure device 2, the image forming apparatus can be used as a copier, a facsimile, a laser printer, or the like. For example, the exposing unit 2 includes a reading mechanism for reading an image from a document, and the reading mechanism can irradiate an optical signal via an optical system such as a lens and a mirror. It can be used as. Further, since the exposure unit 2 is connected to a telephone line via a modem and can emit light corresponding to an electric signal from the modem, the image forming apparatus can be used as a facsimile. Furthermore,
Since the exposing device 2 can emit a laser beam corresponding to an external electric signal, the image forming apparatus can be used as a laser printer.

In FIG. 1, a substrate drum 13 is a light element,
For example, it is formed of beryllium, carbon, or the like, has a cylindrical shape, and forms a closed loop. This substrate drum 1
3 rotates around its cylindrical axis. Due to this rotation, the substrate drum 13 moves along this closed loop. Also,
On the outer surface of the closed loop of the substrate drum 13, a photosensitive layer 14 made of a semiconductor layer is formed. The charging means 11 for charging the surface of the photosensitive layer 14 includes an X-ray tube 15 provided in the closed loop, an external fixed electrode 16 and a power supply 17. An X-ray shielding plate 20 is provided around the X-ray tube 15.
The X-ray emitted from the X-ray tube 15 is divided into an X-ray 18a emitted toward the charging unit 11 and an X-ray 18b emitted toward the cleaning unit 12. Substrate drum 1
Since 3 is made of a light element, the X-rays 18a and 18b emitted from the X-ray tube 15 pass through the substrate drum 13 and the photosensitive layer 14 efficiently. In addition, the fixed electrode for charging 1
6 is made of a metal plate, and includes a substrate drum 13 and a photosensitive layer 14.
, And is provided outside the closed loop on the surface of the photosensitive layer 14. This charging fixed electrode 16
Is supplied with a voltage V ₀ from the power supply 17. The charging fixed electrode 16 and the power supply 17 constitute an electric field applying unit, and an electric field from the charging fixed electrode 16 to the surface of the photosensitive layer 14 is formed by applying a voltage to the charging fixed electrode 16.

Further, the X-ray tube 15 constituting the charging X-ray generating means also constitutes the erasing X-ray generating means of the charge eliminating section constituting the cleaning means 12. In the cleaning means 12, an erasing fixed electrode 19 is provided outside the closed loop facing the X-ray tube 15 via the substrate drum 13 and the photosensitive layer. This fixed electrode 19 for erasing is grounded. The brush cleaner 7 is provided at a position adjacent to the erasing fixed electrode 19 in the direction in which the substrate drum 13 rotates.

The X-ray tube 15 constituting the charging and erasing X-ray generating means is provided along the central axis of the cylindrical substrate drum 13. Such an X-ray tube 15 is required to uniformly charge and remove the surface of the photosensitive layer 14.
It is preferable to use a long X-ray tube as in this embodiment, rather than arranging a plurality of short X-ray tubes along the central axis of the substrate drum 13. The X-ray tube 15 generates X-rays having an energy range of 1 to 20 keV.

Next, the charging mechanism of the image forming apparatus having such a structure will be described with reference to FIG. In the figure, the same parts as those in FIGS. 1 and 2 are denoted by the same reference numerals, and description thereof will be omitted.

As shown in FIG. 3A, the atmosphere between the fixed electrode 16 for charging in the charging means 11 and the photosensitive layer 14 is ionized by the irradiation of the X-rays 18a from the X-ray tube 15, and the gas ion Occurs. Positive polarity (+) of this gas ion
The charged gas ions are guided to the surface of the photosensitive layer 14 by the electric field generated by the electric field applying means. Accordingly, the surface of the photosensitive layer 14 is charged with the positive charge 31. In the present embodiment, since the long X-ray tube is used as the X-ray tube 15 as described above, the air on the surface of the photosensitive layer 14 is uniformly irradiated with X-rays, and is sandwiched between the fixed electrodes 16 for charging. Gas ions are uniformly generated in the atmosphere. Therefore, the positive charge (+) is uniformly charged on the surface of the photosensitive layer 14.

The polarity of the electric charge charged on the surface of the photosensitive layer 14 can be set to a desired polarity by the polarity of the voltage applied to the fixed electrode 16 for charging. Therefore,
Depending on the polarity (+) and (-) of the toner used, the photosensitive layer 1
The polarity of the charge charged on the surface of No. 4 can be arbitrarily selected. The surface potential of the photosensitive layer 14 can be set to a desired charging potential by selecting a voltage value to be applied to the fixed electrode 16 for charging. Therefore, by selecting this voltage value, the charge amount Q of the gas ions charged on the surface of the photosensitive layer 14 can be freely controlled. In addition, photosensitive layer 1
Since the charging potential of No. 4 can be strictly controlled, the quality of an image to be formed is improved. By such a charging mechanism, the surface of the photosensitive layer 14 is charged.

Next, the erasing mechanism of the latent image charge in the image forming apparatus will be described with reference to FIG.

The cleaning unit 1 is rotated from the fixing unit 5 to rotate.
The atmosphere on the photosensitive layer 14 moved to 2
And X-rays 18 from the X-ray tube 15 transmitted through the photosensitive layer 14
b is irradiated. By the irradiation of the X-rays 18b, the atmosphere on the photosensitive layer 14 is ionized, and gas ions are generated. Of the generated gas ions, the positively charged gas ions are the negatively charged toner 32 remaining on the surface of the photosensitive layer 14.
To neutralize the charge. At the same time, the X-ray tube 15
X-rays 18b emitted from the substrate generate carriers inside the photosensitive layer 14 to neutralize and eliminate the electrostatic latent image formed on the photosensitive layer 14. The neutralized residual toner on the photosensitive layer 14 is removed by the brush cleaner 7, and the surface of the photosensitive layer 14 is cleaned. Due to such an erasing mechanism, the surface of the photosensitive layer 14 is neutralized and cleaned.

Next, the operation of the image forming apparatus according to the present embodiment will be described.

In FIG. 1, the charging means 11 is operated while rotating the substrate drum 13 to uniformly charge the surface of the photosensitive layer 14 disposed on the outer surface of the substrate drum 13 by the charging mechanism described above. You. When the charged photosensitive layer 14 moves to the position of the exposure device 2 with the rotation of the substrate drum 13, an electrostatic latent image corresponding to an image to be formed by irradiation of light from the exposure device 2 is formed on the surface thereof. Formed sequentially. Then, when the photosensitive layer 14 moves to the developing device 3, toner, which is a colored fine particle charged to a polarity different from that of the electrostatic latent image, is attached to a region of the electrostatic latent image. This toner is usually black, but may be of another color. Further, when the photosensitive layer 14 moves to the transfer unit 4, a recording medium is supplied between the substrate drum 13 and the transfer unit 4 in synchronization with the movement, and the toner on the surface of the photosensitive layer 14 is transferred to the transfer unit 4. Transferred by electrostatic force from After the transfer, the recording medium is transferred to the position of the fixing device 5, and the toner is fixed by heating in the fixing device 5, so that a desired image is formed on the recording medium. On the other hand, although the residual toner exists in the photosensitive layer 14 after the toner transfer, as described above, the cleaning unit 12 surely removes and cleans the charge, and the photosensitive layer 14 returns to the initial state. Then, after the photosensitive layer 14 is charged again by the charging means 11,
Each step of exposure, development, transfer and cleaning is repeated,
An image is formed.

(Embodiment 2) In the image forming apparatus according to Embodiment 1, the case where the cylindrical substrate drum 13 is used as the base for moving the photosensitive layer 14 has been described.
The substrate is not limited to this. For example, as shown in FIG. 4, a sheet film belt 41 made of a light element formed in a closed loop may be used as the base. In this case, a photosensitive member 42 made of an organic optical semiconductor is formed on the surface of the sheet film belt 41 outside the closed loop, and the driving roller 43 moves the belt 41 along the closed loop. Then, the X-ray tube 15 constituting the X-ray generating means and the X-ray erasing means is provided in the closed loop as in the above embodiment. Also, X via the belt 41 and the photoreceptor 42
A charging fixed electrode 16 and an erasing fixed electrode 19 are provided outside the closed loop facing the wire tube 15 to constitute a charging unit 11 and a cleaning unit 12, respectively. Even in such a configuration, the electric charge 44 is charged on the surface of the photoconductor 42 by the X-rays 18a emitted from the X-ray tube 15. Also,
The X-rays 18 b emitted from the X-ray tube 15 cause the photoconductor 4 to emit light.
The charge of the toner remaining on the surface 2 is neutralized, and the electrostatic latent image remaining on the photoconductor 42 is eliminated. Therefore, even in such a configuration, the same effect as that of the first embodiment can be obtained.

The flash lamps 45a and 45b constitute an exposure device, and toner is sprinkled by the developing device 46 on the electrostatic latent image formed by the exposure device.
The accompanying image is transferred to a recording medium by the transfer device 47.

[0023]

As described above, according to the present invention, the X-rays emitted from the charging X-ray generating means in the non-contact charging means pass through the substrate and generate gas ions on the photosensitive layer. The gas ions are guided to the surface of the photosensitive layer by the electric field generated by the electric field applying means, and charge the surface of the photosensitive layer. Further, the X-rays emitted from the erasing X-ray generating means in the cleaning means also pass through the substrate and generate gas ions on the photosensitive layer. The gas ions neutralize the colored fine particles remaining on the surface of the photosensitive layer. The X-rays emitted from the erasing X-ray generating means generate carriers in the photosensitive layer,
This carrier causes the electrostatic latent image formed on the photosensitive layer to disappear in a non-contact manner.

For this reason, charging and discharging of the photosensitive layer can be performed without using a conventional corona discharge. Therefore, according to the image forming apparatus of the present invention, ozone, NOx and dust are not generated. Therefore, the problem that the electrodes which are the peripheral parts of the charging unit and the static elimination unit are oxidized and the peripheral parts are deteriorated as in the related art is solved. Further, there is no possibility of fire or the like due to corona discharge. Further, an image forming apparatus that is preferable in the global environment is realized.

Further, since the X-ray generating means is provided inside the closed loop of the base, it is not necessary to provide a corona discharge section which must be installed outside the closed loop as in the conventional case. For this reason, a small-sized image forming apparatus can be realized.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating an image forming apparatus according to an embodiment of the present invention.

FIG. 2 is a perspective view schematically showing a charging unit and a cleaning unit of the image forming apparatus according to the embodiment.

FIG. 3 is a partially enlarged cross-sectional view illustrating a charging mechanism and an erasing mechanism of the image forming apparatus according to the embodiment.

FIG. 4 is a cross-sectional view illustrating an image forming apparatus according to a modification of the embodiment.

FIG. 5 is a diagram illustrating a basic configuration of a conventional image forming apparatus.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 11 ... Charging means, 12 ... Cleaning means, 13 ... Substrate drum, 14 ... Photosensitive layer, 15 ... X-ray tube, 16 ... Charging fixed electrode, 17 ... Power supply, 18a, b ... X-ray, 19 ... Erase fixed electrode , 20 ... X-ray shielding plate.

Continuation of the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) G03G 15/02 G03G 21/06

Claims (5)

(57) [Claims] 1. A substrate formed in a closed loop shape and moving along the closed loop, a charging means for charging a surface of a photosensitive layer formed on an outer peripheral surface of the substrate, and exposing the charged surface of the photosensitive layer to light. Exposure means for forming an electrostatic latent image corresponding to an image to be formed, developing means for attaching colored fine particles to the electrostatic latent image, and transfer of colored fine particles attached to the area of the electrostatic latent image to a recording medium An image forming apparatus comprising: a transfer unit that performs transfer, a fixing unit that fixes the colored fine particles transferred to the recording medium, and a cleaning unit that cleans the colored fine particles remaining on the surface of the photosensitive layer. Is formed of a light element, and the charging means is a charging X-ray generator provided in the closed loop for ionizing the atmosphere on the surface of the photosensitive layer by irradiating X-rays transmitted through the substrate and the photosensitive layer. And an electric field applying means for guiding gas ions generated by the ionization to the surface of the photosensitive layer by an electric field, wherein the cleaning means is configured such that the colored fine particles remain by irradiation of X-rays transmitted through the substrate and the photosensitive layer. The erasing X provided in the closed loop for ionizing the air on the photosensitive layer and generating carriers in the photosensitive layer.
An image forming apparatus comprising a line generating unit. 2. The image forming apparatus according to claim 1, wherein said charging X-ray generating means and said erasing X-ray generating means are constituted by the same X-ray generating means. 3. The electric field applying means includes an electrode provided outside the closed loop on the surface of the photosensitive layer facing the X-ray generating means via the substrate and the photosensitive layer, and applies a voltage to the electrode. The image forming apparatus according to claim 1, further comprising a power supply. 4. The image forming apparatus according to claim 1, wherein said substrate is a cylindrical drum. 5. The image forming apparatus according to claim 1, wherein the base is a closed loop belt.